Paternal expenditure is related to brood sex ratio in polygynous great reed warblers |
| |
Authors: | I Nishiumi Satoshi Yamagishi Hiromi Maekawa Chikashi Shimoda |
| |
Institution: | (1) Department of Biology, Faculty of Science, Osaka City University, Sugimoto, Sumiyoshi-ku, Osaka 558, Japan, JP |
| |
Abstract: | In many polygynous animals, parents invest more heavily in individual sons than in daughters. However, it is unclear if these
differences in investment are a consequence of sex differences in the demand of offspring related to sexual size dimorphism
or a consequence of parental manipulation. Here, we report on parental food delivery frequency in relation to brood size and
brood sex ratio in a wild population of polygynous great reed warblers Acrocephalus arundinaceus. We used the polymorphic microsatellite loci on the Z chromosome to sex chicks. We found that paternal feeding frequency
(times/h per nest) increased not with brood size, but with the proportion of males in the brood, although the demand per nest
was more closely related to brood size than to brood sex ratio. Additionally, the increase in rate of paternal feeding frequency
in relation to the brood sex ratio was much higher than the increase in rate of nestling food demands. Maternal feeding frequency
was independent of both brood size and brood sex ratio. These results strongly suggest that fathers preferentially invest
in their sons. We propose that parents can afford sex-biased parental care in animals in which food provisioning is enough
for all offspring to survive.
Received: 22 January 1996/Accepted after revision: 30 June 1996 |
| |
Keywords: | Parental manipulation Paternal feeding Brood sex ratio Microsatellite DNA Great reed warbler |
本文献已被 SpringerLink 等数据库收录! |
|